How to update an old iMac mid-2011 from 10.7.5 to whatever is most recent

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How to update an old iMac mid-2011 from 10.7.5 to whatever is most recent

Hello,

I have a mid-2011 iMac running 10.7.5 that I haven't used much at all since bringing it into a repair shop. I believed it had a virus of some sort and couldn't run Malwarebytes to figure it out. I didn't have faith I could fix it on my own, so I brought it into a repair shop. Since then, I've used it a handful of times only to back up some files to an exFAT formatted external hard drive (it was replaced by a Thinkpad running Windows 10, so I wanted to be able to work with the files on the laptop). It should be good, but I've been iffy with the iMac since the repair due to the old OS and have avoided doing anything with it.

I'd like to turn it on again and try to get some more files out of it, but I'm worried with such an outdated system, I'm susceptible to malware. I would like to update it to Mac OS 10.13.x if possible to get the new file storage system updated from Mac OS Extended to APFS. I recently bought a Mac Mini M4 and I wanted to format my external drive to APFS, but I would want to have my iMac on OS 10.13.x so I could use the same formatted external hard drive for file backups to both of these computers.

How would I go about upgrading my old iMac? I have a general outline of what I think I should do, but I wanted to ask before doing anything wrong:

Connect to power and turn on the computer (maybe in "safe mode").
Backup files to an external hard drive formatted as exFAT, so I can scan then work through the contents on my Windows laptop. If everything in the backup looks good, I can proceed to the next step. I don't want to do this specific work on my new Mac Mini because I have (hopefully unfounded) paranoia about potential malware going into the new system in case the repair shop wasn't able to get all of it due to the OS 10.7.5 being very outdated even at the time of repair many years ago.
Connect the iMac to my router via ethernet cable.
Find the OS update 10.8.x and upgrade. If everything works, then upgrade to 10.9.x, ..., then 10.13.x. I'm assuming it is possible from a table in this article I found. I am unsure if it's a good idea or possible to just jump straight to 10.13.x in one go rather than one step at a time.
If everything goes well, then I can backup the iMac contents again, but on an external hard drive formatted for APFS.
End up with an up-to-date iMac and up-to-date Mac Mini along with a properly formatted hard drive for them specifically. I think I would do an NTFS external hard drive for my Windows laptop, even though the files will only be readable by my Apple products as far as I understand. I've read about Paragon software for Mac, but I don't want to think too far ahead as to not overwhelm myself even more.

Is there anything wrong with my plan? I can go back to the repair shop I used and have them figure it all out for me, but there are several reasons I'm avoiding this. It's far/inconvenient for me to get to, will cost money (that I would rather be used on buying more external hard drives), and I won't learn how to effectively out figure this situation on my own. However, I'm open to the option if necessary.

If I'm missing any information, breaking any forum rules, or otherwise causing problems with my post, please let me know and I'll try to rectify them. Thank you in advance for any help given for my situation.

Posted on Feb 5, 2025 4:04 PM

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Answer 1

Top-ranking reply

D.I. Johnson

Level 8

35,303 points

Feb 5, 2025 7:43 PM in response to WantToLearnPlease

You've certainly waited long enough to upgrade your Mac.

The 2011 can run up to macOS 10.13 High Sierra. Unfortunately, the clock has run out on that and all previous versions of the macOS, so upgrading now may be problematic. High Sierra is still available to download, but the server connection has been flakey and Apple have chosen to ignore the problem.

When it comes time to upgrade the iMac, the first thing to do is to create a Time Machine backup of your system as it is now. If something goes wrong you may need to use that to get the computer running again.

I think it best to upgrade in as few steps as possible because of the temperamental nature of the servers for these old OS versions. So upgrade to the required OS 10.8 first, then make the jump to 10.13.

You already have the link to download 10.8 as you noted in your original post. So get that and apply it to you iMac.

After you have 10.8 installed, then you can download the macOS 10.13 High Sierra installer from the App Store here:

https://itunes.apple.com/app/macos-high-sierra/id1246284741

This download will place the "Install macOS High Sierra" app in the Applications folder. Double-click the installer to begin the upgrade process.

There has been an issue lately with folks being unable to download High Sierra because of a server error. The info in this article can help you get past that if you need to. See Fix #3 here: https://mrmacintosh.com/how-to-fix-the-recovery-server-could-not-be-contacted-error-high-sierra-recovery-is-still-online-but-broken/

Assuming all goes well, your old iMac will be running High Sierra, the latest OS that it can. Make another Time Machine backup so you can fall back on it if needed in the future.

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Answer 2

padams35

Level 4

3,613 points

Feb 6, 2025 6:52 AM in response to WantToLearnPlease

Your upgrade plan will work and will need to be done in at least two steps. I would suggest splitting the difference and upgrading from 10.7->10.10->10.13.

Since malware is a concern you might wish to instead create bootable USB installers (Create a bootable installer for macOS - Apple Support). Those will allow you to erase the internal drive, make a clean install, and then manually transfer only important files. You should be able to go directly from 10.7->10.13 with a USB installer, but it might be good to also make a 10.11 installer just in case as a dissimilar backup.

Finally you may need to plan on hardware upgrades if you have a baseline configuration. MacOS 10.11+ really wants either 8GB+ RAM to minimize swap space use on disk or else an SSD for fast memory/disk swapping.

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Answer 3

Feb 28, 2025 9:27 PM in response to WantToLearnPlease

It seems like a success since I was able to update to 10.13.6. I started taking notes during the process because of the hurdles I came across. I'm not sure, but hopefully these notes will be helpful to anyone else going through the process of updating their old macs.

When backing up my files to an external hard-drive formatted to exFAT, it took around 4 hours for ~250gb of stuff.
Attempted to install 10.8.x, but failed to authenticate. Changed the date on the iMac ("sudo date 0814120015" worked for me) and tried again. Estimate was 35 minutes, but took around an hour.
Skipped 10.9.x because it wasn't available from Apple
Attempted to install 10.10.x through Apple's download and making bootable drives, but failed even after changing the date on the computer.
Went back to try 10.9.x by using a bootable drive method post by startergo on January 31, 2023. Install estimate was 50 minutes, but completed faster at around 40 minutes for everything. At this point I noticed that I should've been counting unpacking, downloading, installing, and completing as separate things, but it took around an hour total with these included.
Skipped 10.10.x again. I had to skip 10.11.x as well since it had the same issues.
Attempted to install 10.12.x. I noted a 33 minutes estimate, but it took 50 minutes, plus some before and after.
Connected to internet via ethernet cable temporarily just to download 10.13.x, then disconnected. This had a 45 minute estimate that ended up being 65 minutes, plus some time before and after.

Overall, I spent around 2 work days worth of time over two weekends on this project, mostly to troubleshoot & learn about bootable drives. Otherwise, it was just a bunch of waiting around and doing other things on the side. I downloaded Firefox 115 ESR on a separate computer as to not use the outdated Safari and Firefox, since that is the only browser I knew of that would be safe on the machine. To my dismay, I also found a relatively recent post saying that it's end-of-support is March 2025. I don't believe any newer version will run on 10.13.6. I think the most I can do is use the machine offline for Photoshop CS5. I saw you can sort of fool the computer into upgrading to later operating systems, but it doesn't seem worth it for my case, especially considering the iMac hardware compared to something new like my Mac Mini. There is a possibility that I could use some sort of Linux OS to breathe life back into the iMac, but that's a project for another time.

I considered spending to upgrade the parts. First, 2.5GHz Intel i5 to 2.7GHz or 2.8GHz, then 8gb RAM to 32gb since I read you need a better CPU to accept the RAM upgrade. During the research, I remembered when I went to the repair shop that one of the workers told me 8gb is the maximum for my specific computer build, probably due to my 2.5GHz CPU. Second, I would've wanted to upgrade to a 1TB HDD or SSD. After looking at prices after I completed the software updates, it seemed silly to spend hundreds just to tinker when it would probably be better spent on more external drives or other tech/tools for my newer stuff.

I looked into using it as a monitor (in particular something I saw called "target display mode") but as far as I can tell, it was for older macs and I won't be able to use it for my Mac Mini. I found a modification on Youtube to turn it into a monitor, but it seems like a dead kickstarter & probably out of my skillset to figure out. It feels like such a waste since to this day it's probably been the best looking monitor I've owned up until buying an OLED TV. I can't believe a screen from 2011 is still that good looking (at least to my eyes).

It was cool seeing the incremental subtle visual changes going through each Mac OS. It was unfortunate I had to skip & miss 2 out of 6 updates, but it was good to see regardless. The minimum RAM needs went up from 2gb just over 3gb due to the updates, so I guess I was lucky I made the choice to upgrade from 4gb to 8gb years ago.

Although it seems like it reached end-of-life, I'll keep it in storage for now. It'll be difficult to find a good box and protective fill to protect the screen since the original packaging is long gone. Hopefully one day I'll be able to recycle or reuse it in some way, but for now it's the end of the road. Thank you all for the your perspectives and help. I appreciate how kind you all were with the advice towards my personal project and am happy to have been able to figure it out.

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Answer 4

Feb 6, 2025 2:38 AM in response to WantToLearnPlease

Upgrading to 10.8 (Mountain Lion) might not be enough to let you access the High Sierra App Store link in the article How to download and install macOS - Apple Support .

You might need to download the .DMG file containing the Sierra installer (with the aid of a modern Mac or PC), transfer the .DMG file to the old Mac (on a USB drive), open the DMG (mount the disk image), and then run the Sierra installer inside.

Then cross your fingers and pray that Apple's servers are in such a condition that upgrading from Sierra to High Sierra still works …

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Answer 5

rkaufmann87

Level 10

148,588 points

Feb 5, 2025 7:01 PM in response to WantToLearnPlease

To migrate information from your 2011 iMac to the new MM, please follow the steps in Setup Assistant and Migration Assistant. It sounds like you have already setup the MM, so just follow the info for MA.

Please take your time and read it carefully, it answers ALL the questions questions you have!!!!!!!!!!!!!!!!!

We do not support MS Windows so we cannot counsel you on how to format the External Hard Disk you intend to use with your Windows machine. If you intend to share an External Hard Disk with the Mac and Windows box then I'd counsel against that and simply use iCloud to sync your files and/or setup file sharing on both the MM and the Windows machine. Apple explains files sharing setup in File sharing

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How to update an old iMac mid-2011 from 10.7.5 to whatever is most recent

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